/*
 * Copyright (C) 2006-2007 The Android Open Source Project
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

#undef LOG_TAG
#define LOG_TAG "CursorWindow"

#include <androidfw/CursorWindow.h>
#include <utils/Log.h>

#include <cutils/ashmem.h>
#include <sys/mman.h>

namespace android {

    CursorWindow::CursorWindow(const String8 &name, int ashmemFd,
                               void *data, size_t size, bool readOnly) :
            mName(name), mAshmemFd(ashmemFd), mData(data), mSize(size), mReadOnly(readOnly) {
        mHeader = static_cast<Header *>(mData);
    }

    CursorWindow::~CursorWindow() {
        ::munmap(mData, mSize);
        ::close(mAshmemFd);
    }

    status_t
    CursorWindow::create(const String8 &name, size_t size, CursorWindow **outCursorWindow) {
        String8 ashmemName("CursorWindow: ");
        ashmemName.append(name);

        status_t result;
        int ashmemFd = ashmem_create_region(ashmemName.string(), size);
        if (ashmemFd < 0) {
            result = -errno;
        } else {
            result = ashmem_set_prot_region(ashmemFd, PROT_READ | PROT_WRITE);
            if (result >= 0) {
                void *data = ::mmap(NULL, size, PROT_READ | PROT_WRITE, MAP_SHARED, ashmemFd, 0);
                if (data == MAP_FAILED) {
                    result = -errno;
                } else {
                    result = ashmem_set_prot_region(ashmemFd, PROT_READ);
                    if (result >= 0) {
                        CursorWindow *window = new CursorWindow(name, ashmemFd,
                                                                data, size, false /*readOnly*/);
                        result = window->clear();
                        if (!result) {
                            LOG_WINDOW("Created new CursorWindow: freeOffset=%d, "
                                               "numRows=%d, numColumns=%d, mSize=%d, mData=%p",
                                       window->mHeader->freeOffset,
                                       window->mHeader->numRows,
                                       window->mHeader->numColumns,
                                       window->mSize, window->mData);
                            *outCursorWindow = window;
                            return OK;
                        }
                        delete window;
                    }
                }
                ::munmap(data, size);
            }
            ::close(ashmemFd);
        }
        *outCursorWindow = NULL;
        return result;
    }

/*    status_t CursorWindow::createFromParcel(Parcel *parcel, CursorWindow **outCursorWindow) {
        String8 name = parcel->readString8();

        status_t result;
        int ashmemFd = parcel->readFileDescriptor();
        if (ashmemFd == int(BAD_TYPE)) {
            result = BAD_TYPE;
        } else {
            ssize_t size = ashmem_get_size_region(ashmemFd);
            if (size < 0) {
                result = UNKNOWN_ERROR;
            } else {
                int dupAshmemFd = ::dup(ashmemFd);
                if (dupAshmemFd < 0) {
                    result = -errno;
                } else {
                    void *data = ::mmap(NULL, size, PROT_READ, MAP_SHARED, dupAshmemFd, 0);
                    if (data == MAP_FAILED) {
                        result = -errno;
                    } else {
                        CursorWindow *window = new CursorWindow(name, dupAshmemFd,
                                                                data, size, true *//*readOnly*//*);
                        LOG_WINDOW("Created CursorWindow from parcel: freeOffset=%d, "
                                           "numRows=%d, numColumns=%d, mSize=%d, mData=%p",
                                   window->mHeader->freeOffset,
                                   window->mHeader->numRows,
                                   window->mHeader->numColumns,
                                   window->mSize, window->mData);
                        *outCursorWindow = window;
                        return OK;
                    }
                    ::close(dupAshmemFd);
                }
            }
        }
        *outCursorWindow = NULL;
        return result;
    }*/
/*

    status_t CursorWindow::writeToParcel(Parcel *parcel) {
        status_t status = parcel->writeString8(mName);
        if (!status) {
            status = parcel->writeDupFileDescriptor(mAshmemFd);
        }
        return status;
    }
*/

    status_t CursorWindow::clear() {
        if (mReadOnly) {
            return INVALID_OPERATION;
        }

        mHeader->freeOffset = sizeof(Header) + sizeof(RowSlotChunk);
        mHeader->firstChunkOffset = sizeof(Header);
        mHeader->numRows = 0;
        mHeader->numColumns = 0;

        RowSlotChunk *firstChunk = static_cast<RowSlotChunk *>(offsetToPtr(
                mHeader->firstChunkOffset));
        firstChunk->nextChunkOffset = 0;
        return OK;
    }

    status_t CursorWindow::setNumColumns(uint32_t numColumns) {
        if (mReadOnly) {
            return INVALID_OPERATION;
        }

        uint32_t cur = mHeader->numColumns;
        if ((cur > 0 || mHeader->numRows > 0) && cur != numColumns) {
            ALOGE("Trying to go from %d columns to %d", cur, numColumns);
            return INVALID_OPERATION;
        }
        mHeader->numColumns = numColumns;
        return OK;
    }

    status_t CursorWindow::allocRow() {
        if (mReadOnly) {
            return INVALID_OPERATION;
        }

        // Fill in the row slot
        RowSlot *rowSlot = allocRowSlot();
        if (rowSlot == NULL) {
            return NO_MEMORY;
        }

        // Allocate the slots for the field directory
        size_t fieldDirSize = mHeader->numColumns * sizeof(FieldSlot);
        uint32_t fieldDirOffset = alloc(fieldDirSize, true /*aligned*/);
        if (!fieldDirOffset) {
            mHeader->numRows--;
            LOG_WINDOW("The row failed, so back out the new row accounting "
                               "from allocRowSlot %d", mHeader->numRows);
            return NO_MEMORY;
        }
        FieldSlot *fieldDir = static_cast<FieldSlot *>(offsetToPtr(fieldDirOffset));
        memset(fieldDir, 0, fieldDirSize);

        LOG_WINDOW("Allocated row %u, rowSlot is at offset %u, fieldDir is %d bytes at offset %u\n",
                   mHeader->numRows - 1, offsetFromPtr(rowSlot), fieldDirSize, fieldDirOffset);
        rowSlot->offset = fieldDirOffset;
        return OK;
    }

    status_t CursorWindow::freeLastRow() {
        if (mReadOnly) {
            return INVALID_OPERATION;
        }

        if (mHeader->numRows > 0) {
            mHeader->numRows--;
        }
        return OK;
    }

    uint32_t CursorWindow::alloc(size_t size, bool aligned) {
        uint32_t padding;
        if (aligned) {
            // 4 byte alignment
            padding = (~mHeader->freeOffset + 1) & 3;
        } else {
            padding = 0;
        }

        uint32_t offset = mHeader->freeOffset + padding;
        uint32_t nextFreeOffset = offset + size;
        if (nextFreeOffset > mSize) {
            ALOGW("Window is full: requested allocation %zu bytes, "
                          "free space %zu bytes, window size %zu bytes",
                  size, freeSpace(), mSize);
            return 0;
        }

        mHeader->freeOffset = nextFreeOffset;
        return offset;
    }

    CursorWindow::RowSlot *CursorWindow::getRowSlot(uint32_t row) {
        uint32_t chunkPos = row;
        RowSlotChunk *chunk = static_cast<RowSlotChunk *>(
                offsetToPtr(mHeader->firstChunkOffset));
        while (chunkPos >= ROW_SLOT_CHUNK_NUM_ROWS) {
            chunk = static_cast<RowSlotChunk *>(offsetToPtr(chunk->nextChunkOffset));
            chunkPos -= ROW_SLOT_CHUNK_NUM_ROWS;
        }
        return &chunk->slots[chunkPos];
    }

    CursorWindow::RowSlot *CursorWindow::allocRowSlot() {
        uint32_t chunkPos = mHeader->numRows;
        RowSlotChunk *chunk = static_cast<RowSlotChunk *>(
                offsetToPtr(mHeader->firstChunkOffset));
        while (chunkPos > ROW_SLOT_CHUNK_NUM_ROWS) {
            chunk = static_cast<RowSlotChunk *>(offsetToPtr(chunk->nextChunkOffset));
            chunkPos -= ROW_SLOT_CHUNK_NUM_ROWS;
        }
        if (chunkPos == ROW_SLOT_CHUNK_NUM_ROWS) {
            if (!chunk->nextChunkOffset) {
                chunk->nextChunkOffset = alloc(sizeof(RowSlotChunk), true /*aligned*/);
                if (!chunk->nextChunkOffset) {
                    return NULL;
                }
            }
            chunk = static_cast<RowSlotChunk *>(offsetToPtr(chunk->nextChunkOffset));
            chunk->nextChunkOffset = 0;
            chunkPos = 0;
        }
        mHeader->numRows += 1;
        return &chunk->slots[chunkPos];
    }

    CursorWindow::FieldSlot *CursorWindow::getFieldSlot(uint32_t row, uint32_t column) {
        if (row >= mHeader->numRows || column >= mHeader->numColumns) {
            ALOGE("Failed to read row %d, column %d from a CursorWindow which "
                          "has %d rows, %d columns.",
                  row, column, mHeader->numRows, mHeader->numColumns);
            return NULL;
        }
        RowSlot *rowSlot = getRowSlot(row);
        if (!rowSlot) {
            ALOGE("Failed to find rowSlot for row %d.", row);
            return NULL;
        }
        FieldSlot *fieldDir = static_cast<FieldSlot *>(offsetToPtr(rowSlot->offset));
        return &fieldDir[column];
    }

    status_t CursorWindow::putBlob(uint32_t row, uint32_t column, const void *value, size_t size) {
        return putBlobOrString(row, column, value, size, FIELD_TYPE_BLOB);
    }

    status_t CursorWindow::putString(uint32_t row, uint32_t column, const char *value,
                                     size_t sizeIncludingNull) {
        return putBlobOrString(row, column, value, sizeIncludingNull, FIELD_TYPE_STRING);
    }

    status_t CursorWindow::putBlobOrString(uint32_t row, uint32_t column,
                                           const void *value, size_t size, int32_t type) {
        if (mReadOnly) {
            return INVALID_OPERATION;
        }

        FieldSlot *fieldSlot = getFieldSlot(row, column);
        if (!fieldSlot) {
            return BAD_VALUE;
        }

        uint32_t offset = alloc(size);
        if (!offset) {
            return NO_MEMORY;
        }

        memcpy(offsetToPtr(offset), value, size);

        fieldSlot->type = type;
        fieldSlot->data.buffer.offset = offset;
        fieldSlot->data.buffer.size = size;
        return OK;
    }

    status_t CursorWindow::putLong(uint32_t row, uint32_t column, int64_t value) {
        if (mReadOnly) {
            return INVALID_OPERATION;
        }

        FieldSlot *fieldSlot = getFieldSlot(row, column);
        if (!fieldSlot) {
            return BAD_VALUE;
        }

        fieldSlot->type = FIELD_TYPE_INTEGER;
        fieldSlot->data.l = value;
        return OK;
    }

    status_t CursorWindow::putDouble(uint32_t row, uint32_t column, double value) {
        if (mReadOnly) {
            return INVALID_OPERATION;
        }

        FieldSlot *fieldSlot = getFieldSlot(row, column);
        if (!fieldSlot) {
            return BAD_VALUE;
        }

        fieldSlot->type = FIELD_TYPE_FLOAT;
        fieldSlot->data.d = value;
        return OK;
    }

    status_t CursorWindow::putNull(uint32_t row, uint32_t column) {
        if (mReadOnly) {
            return INVALID_OPERATION;
        }

        FieldSlot *fieldSlot = getFieldSlot(row, column);
        if (!fieldSlot) {
            return BAD_VALUE;
        }

        fieldSlot->type = FIELD_TYPE_NULL;
        fieldSlot->data.buffer.offset = 0;
        fieldSlot->data.buffer.size = 0;
        return OK;
    }

}; // namespace android
